Bastiaan “Bas” van Fraassen, professor emeritus of philosophy at Princeton University, has been awarded the 2026 Rolf Schock Prize in Logic and Philosophy.

The Schock Prize in Logic and Philosophy is bestowed by the Royal Swedish Academy of Sciences (KVA). Winners each receive 600,000 Swedish kronor (approximately $66,000).

Professor van Fraassen was awarded the prize “for having developed a compelling empiricist approach to science that has decisively moved beyond logical empiricism, profoundly influenced contemporary philosophy of science, and shaped the debate on scientific realism.”

The KVA prize announcement states:

According to empiricism, we get all our knowledge through our senses. At the same time, there are things we think we know that cannot be directly observed (such as elementary particles and force fields in physics). Therefore, it is impossible to rely solely on observations to know which assumptions are correct. It is conceivable that different theories could lead to exactly the same predictions about what can be observed, but still differ in their assumptions about underlying, unobservable quantities.

Some earlier empiricists argued that such assumptions cannot be seen as true or false statements about reality, an interpretation that has proven deeply problematic and has therefore been generally abandoned in recent years. Instead, constructive empiricism, as formulated by Bastiaan C. van Fraassen, has gained traction.

According to it, one can interpret assumptions about unobservable conditions literally (as statements about reality) while remaining skeptical of claims to knowledge that go beyond what we can observe. The goal of science, which is considered to be developing theories that are consistent with our observations, is achieved in any case.

The full prize announcement, including the winners of the Schock prizes in Mathematics, Visual Arts, and Musical Arts, is here, and you can learn more about Rolf Schock here. The winners will receive their prizes at a ceremony in June.

UPDATE: While the news was spreading about his prize, van Fraassen added a new post at his blog. It’s about Tarski’s Calculus of Systems.